My neighbor's '13 DC SB came with a trifold from the dealership, he's thinking of selling it. I'll check with him and get back soon, located in Saratoga Springs NY area, about 45 minutes north of Albany. pm me if intersted , I'll try and get you two in touch.

This is what I bought. Added some extra weather stripping around the gate and corners and have had no major issues. Have had some occasional small leaks, but I keep a plastic tub back there in the winter anyways.